Apparatus for determining the density of flowing samples including a primary and secondary recorder



SAMPLES M. H. PELAVIN MaylZ, 1970 APPARATUS FOR DETERMINING THE DENSITY OF FLOWING INCLUDING A ,PRIMARY AND SECONDARY RECORDER Filed Feb. 25, 1956 7 Sheets-Sheet 1 I N VEN TORI 1 mm. N 1 11241; Y

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' INC Filed Feb. 25, 1966 y 12, 1970 MQH. PEL-AVI 3,512,163

APPARATUS DET IN T DENS FLOWING SAMPLES ING RI Y SECOND RECO R heets sheet 2 M. H. PELAVIN APPARATUS FOR DETERMINING THE DENSITY OF FLOWING SAMPLES INCLUDING A PRIMARY AND SECONDARY RECORDER Filed Feb. 23,,

'7 Sheets-Sheet 5 k 3 M01 E MHG ow 3 \w 8 ATI'OPNEY May 2,

Filed Feb.

APPARATUS FOR DETERMINING M. H. PELAVIN THE DENSITY OF FLOWING SAMPLES INCLUDING A PRIMARY AND SECONDARY RECORDER 25, 1966 aa 19o ER 294 268 1 O VIIWI'II'A 262 1 .5. m 25s I 3 w --210 EE T F444 I Z58 INVENTOR,

7 Sheets-Sheet 4 h Ql [4 T ming AFFOP/YC'Y May 12, 1970 M. H. PELAVIN 6 APPARATUS FOR DETERMINING THE DENSITY OF FLOWING SAMPLES INCLUDING A PRIMARY AND SECONDARY RECORDER '7 Sheets- Sheet 5 Filed Feb. 25, 1966 Z29 INVENTORS? Wop/yer May 12, 1970 M. H. PELAVIN 3,512,163

APPARATUS FOR DETERMINING THE DENSITY OF FLOWING SAMPLES INCLUDING A PRIMARY AND SECONDARY RECORDER Filed Feb. 23, 1966 7 Sheets-Sheet 6 u.) g INVENTOR! AITOQ/VEY Q) N OJ N, N

May 12, 1970 M. H. PELA'VIN 3,512,163

. APPARATUS FOR DETERMINING THE DENsITY' OF FLOWING SAMPLES INCLUDING A PRIMARY A D SECONDARY RECORDER Filed Feb. 23, 1966 '7 Sheets-Sheet 7 I INVENTORQI Mw @Rm;

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United States Patent M US. Cl. 346-1 11 Claims ABSTRACT OF THE DISCLOSURE Method and apparatus are described for the colorimetric analysis of a plurality of liquid samples which provides that each flow cell is being read at its maximum optical density. To indicate proper phasing of the liquid sample, an auxiliary indicator is connected to at least one flow cell to indicate, or monitor the optical density of the liquid sample as it flows through the flow cell. The auxiliary indicator provides a signal which chronologically overlaps the actual signal read and recorded by the primary recorder and has superimposed thereon a signal indicative of the operative connection of the primary recorder to the corresponding. flow cell. The location of the superimposed signal with respect to the peak, or plateau, of the optical density signal indicates the phasing of the primary recorder with respect to the optical density of the liquid sample.

'This invention relates to the analysis of fluids with respect to one or more substances present in the fluids, and especially to an improved colorimeter for quantitatively analyzing a plurality of fluid samples at substantially the same time.

In the article Multiple Automatic Sequential Analysis by Leonard T. Skeggs, Jr. et al., in Clinical Chemistry, vol. 10, No. 10, October 1964, pp. 918936, there is discussed an apparatus which is adapted to quantitatively analyze each of a plurality of fluid samples for a plurality, such as eight, diiferent substances or constituents therein. Briefly, each of the sample fluids, which may be a body fluid such as blood or urine, is disposed in a respective container. The containers are mounted on a movable support which automatically, sequentially, and intermittently presents each of the containers to an off-take station. An off-take tube is automatically inserted into the presented container and the sample is aspirated therefrom as a stream of fluid. The sequentially aspirated samples are formed into a continuous stream wherein each sample is spaced from the preceding sample by a segment of air. This initial stream of samples is divided into a plurality of quotient streams of samples, each quotient sample being a fractional portion of a respective sample in the initial stream. Each of the quotient streams is treated with a reagent, as taught in the US. Pat. No. 2,797,149 to Leonard T. Skeggs, issued June 25, 1957, to provide a color reaction which is responsive to the concentration of a predetermined substance in each respective fractional sample portion. Each of the quotient streams is passed through a respective colorimeter and the light transmittance at a predetermined wavelength of each fractional sample portion is determined and the equivalent concentration is recorded. In the embodiment shown therein, the respective colorimeters comprise a plurality of respective flow cells and a single light source and light focusing means, which are sequentially and cyclically shifted from flow cell to flow cell. The arrival times of the fractional sample portions from the same sample from the initial stream are sequentially phased so that each of these portions may be examined sequentially in a group.

Patented May 12, 1970 It is desirable that the fractional portions of the same sample from the initial stream of samples not only arrive at their respective flow cells when such flow cells are to be read out to the recorder, but also that the subportion of each such portion which is in the flow cell when such flow cell is being read-out be at its maximum optical density, since it is the maximum optical density of a treated sample which is responsive to the constituent of interest therein. To achieve this result, the running time of each of the quotient streams, from the time it leaves the off-take tube to the time it reaches its flow cell, must be accurately adjusted in phase with the other quotient streams and the means for reading out the signal to the recorder.

It is, therefore, an object of this invention to provide a means for indicating the relationship of the recorded signal to the maximum signal generated at the flow cell, to make certain that the maximum optical density is being recorded.

According to this invention, an auxiliary indicator is provided for continuously indicating over an interval of time the signal generated by a quotient sample while the signal is made available to the primary recorder for a shorter interval of time whereby to monitor the phasing of the peak signal.

These and other objects, features and advantages will i become apparent upon consideration of the following specification taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view in elevation of a colorimeter em- Ibqying this invention, taken along the plane 1-1 of FIG. 2 is a view in plan, partially disassembled, taken along the plane 2-2 of FIG. 1;

FIG. 3 is a view in elevation, of a detail of FIG. 1;

FIGS. 4, 5, 6, 7, =8 and 9 are views in elevation, in crosssection, taken along respective planes 4-4, 5-5, 6-6, 7-7, 8-8 and 9-9 of FIG. 3;

FIG. 10 is an exploded perspective view of a flow cell and optics assembly of FIG. 3;

FIG. 11 is a pictorial view of a system embodying the colorimeter of FIG. 1;

FIG. 12 is a view in elevation of a quotient stream phasing means;

FIG. 13 is a view in elevation, in cross-section, taken along the plane 13-13 of FIG. 12;

FIG. 14 is a view in elevation of ing means of FIG. 12; and

FIGS. 15 and 16 are detail views, in cross-section, of the phasing means of FIG. 12.

A colorimeter 8 embodying this invention is shown in FIGS. 1, 2 and 3 as including a base member 10 having a lower annular, vertically elongated portion 12; which is supported by a plurality of feet portions 14 above a ground level; an inwardly downwardly sloped, annular, laterally elongated portion 16; a lower, outwardly downwardly sloped, annular, laterally elongated portion 18, having a central aperture 20; an inner annular, vertically elongated castellated portion 22; an outer, annular vertically elongated castellated portion 22; an outer, annular vertically elongated portion 24, and an upper, horizontal, laterally elongated portion 26, having a central aperture 28. An upper, tubular housing 30 having an external, annular flange 32 is fixed coaxially over and into the upper, central aperture 28 by a plurality of machine screws 33. A tube 34 of light permeable material, such as a heat resistant glass, is disposed coaxially over the housing 30, and is held in place by a plurality of spring fingers 36 fixed to the housing 30 by a respective plurality of machine screws 38. The housing 30 also has an internal, segmented, annular flange 40. A triangular shaped, brackpartially in cross-section,

a part of the phaset 42 is fixed to the segmented flange 40 by a plurality of machine screws 44. A lamp base assembly 46 is mounted to the bracket by a spring loaded bayonet arrangement and supports a lamp 48. A pair of electrical conductors 50 are soldered to the contacts of the lamp and lead to a regulated source of voltage, not shown. A lower, tubular housing 52 is fixed to the base member coaxially below the lower central aperture 20 by a plurality of machine screws 54. A fan and motor assembly 56 is fixed coaxially below and to the housing 52 by a plurality of bolts 58. This assembly serves to pass air in under the base member portion 12 and up through the tube 34 past the lamp 48.

A plurality of upstanding posts 60 are threaded at their lower ends 62 and are thereby fixed to the base member portion 22. A plurality of annular plates 64 are fixed to the upper ends of the posts 60 by a plurality of machine screws 66. A side-cover 68 is fitted over the base member and is fixed thereto by a plurality of machine screws 70 threaded into the plates 64 and an annular bracket 72 abutting the base member portion 24. A plurality of indicator lamp base assemblies 74 are fixed to apertures in the annular plates 64 and have respective lamps 76 disposed therein. A top-cover 78, having a central chimney portion 80, is disposed on the top of the side-cover 68. The top-cover 78 has a plurality of apertures 82 therein which respectively pass a lamp 76 therethrough, so that the top-cover is supported on the lamp base assemblies and spaced above the top portion 84 of said side-cover. The chimney portion is disposed coaxially above the tube 34 and has a plurality of side apertures 86. The top-cover also has a plurality of apertures 88 to pass adjusting screws as will be hereinafter described.

An annular body member 90 is disposed above and concentric with the base member upper portion 26, and is fixed thereto by machine screws, not shown. This body member is divided into a plurality of pie shaped segments 91, e.g., sixteen, each having an arc of 21. Each body segment 91 has a lower groove 92, and an upper groove 94 which is interrupted by a projection 96 in an upper surface which is at an angle of 10 to the horizontal. A plurality of lens assemblies 98, flow cell assemblies 100 and light detector assemblies 101 are each respectively disposed at each body segment.

Each lens assembly 98 comprises an upper lens block 102 and a lower lens block 104 which support four lenses 106, 108, 110, 112 on a common axis which is at an angle of 10 to the horizontal. The lens blocks are cemented together, a glass cover 114 is cemented over the rear aperture, and side plates 116 are cemented to the sides. The lower lens block (and the upper lens block) has a projection 118 which is interrupted at 119 and which is adapted to interfit with the upper groove 94 of the body segment 91. The lens assembly may be slid along the common axis, within the limits provided by the interruptions of the projection and the groove to vary the focal point of the beam of light from the lamp 48 which is focused by the lens assembly. An L shaped clamp bracket 120 is fixed to the body segment 91 by a machine screw 122, has a clamping screw 124 which bears against the top of the lens assembly, and has a central aperture 126 to pass the light beam through to the flow cell assembly.

A beam control assembly 130 includes a channel 132 which is fixed to the body segment 91 by two machine screws 134 and has a central aperture 136 to pass the light beam through to the flow cell assembly. Two shutter blades 138 are pivotally mounted on a stud 140 to the channel 132. Each blade 138 has a semi-circular cut-out 142, a slot 144 and a pin 146. A hair pin spring 148 is mounted on the stud 140 and extends between the two pins 146 to bias the cut-outs 142 apart. A stud 149, having a head 150, passes through a slot 152 in the channel 132 and both of the slots 144 of the two blades 138, and is secured with a C clip 154. An adjustment screw 156 is threaded through a nut 158, which nut is fixed to the channel 132 by two machine screws 160, and is captured in the head to oppose the bias of the spring 148. A slide 162 has a central slot 164 which passes the stud 149 and the C clip 154. When the slide is pushed down, as shown in FIG. 3, the slot 164 passes the light beam to the flow cell assembly; when the slide is up, the lower portion of the slide obturates the light beam. Operation of the adjustment screw 156 enlarges or diminishes the aperture provided by the blades and controls the intensity of the light beam passed to the slot 164.

The flow cell assemblies 100 and the light detector assemblies 101 are each mounted in companion sets on a cradle 166. The flow cell 168 comprises an integral glass tube having a fluid inlet 170, a debubbler outlet 172, a slight passageway 174 and a waste outlet 176. The flow cell 168 is cemented into a flow cell holder 178 having a handle 180 and one or two interference filters 182 and 184. The filters and the sight passageway have a common longitudinal axis. The holder 178 is secured to the cradle 166 by a locating pin 186, and by a bolt 188 which threads into an insert 190 in the cradle.

The light detector assembly 101 includes a housing 190 which has a cover 192 and is fixed to the cradle by two machine screws 194. Each assembly has as a detector either a photocell 196 or a vacuum tube detector 198 mounted therein. The front of the housing has an aperture 200 therein in which are disposed an aperture baffle 201 and a biasing spring 204, which are retained by an apertured plate 206 fixed to the housing by two machine screws 208. The spring 204 biases the apertured bafile 201 against the rear of the flow cell holder 178 to provide a lighttight path from the sight passageway to the light detector.

The cradle 166 is supported on a bracket 210 which is fixed to a block 212 by a bolt and nut 213. A rod 214 and a rod 216 are fixed at their lower ends in the block 212. The upper end of the rod 214 slidably fits in a slot 218 in the cradle. The upper end of the rod 216 is threaded and slidably fits through a bore 220 in the cradle. A helical spring 222 is disposed over the rod 216 between the block and the cradle and biases them apart. A nut 224 is threaded onto the projecting upper end of the rod 216 and bears against the upper surface of the cradle. The nut 224 adjusts the vertical position of the cradle against the bias of the spring 222. A screw 226 having a cone shaped end is threaded into a bore 227 in the cradle and bears against a rod 228 which is disposed in a bore 229 communicating with the bores 220 and 227. Advancement of the screw 226 clamps the rod 228 against the rod 216. The bracket 210 has an upper surface 228 which is at an angle of 10 to a lower surface 227. The lower surface 227 of the bracket is adapted to be releasably mounted on the horizontal base member portion 26 with the forward end of the bracket passing through the lower groove 92 of the body segment 91. The body segment 91 has a spring loaded, captured ball detent 230, the ball of which is adapted to engage a hole 232 in the forward end of the bracket. The rearward end of the bracket is adapted to be releasably mounted on the base member portion 22 by means of a bolt 234 whose head bears on a clamping plate 236, and whose shank passes through a hole in the clamping plate, through an enlarged hole 238 in the bracket 210, and into a threaded hole in the base member portion 22.

The assemblage 240 of the flow cell assembly 100, the light detector assembly 101, the block 212 and the bracket 210 may be adjusted horizontally-laterally with respect to the common axis of the lens assembly 98 by means of two pins 242 and 244, or the post 60 and one pin 244, respectively, upstanding from the base member portion 22 on each side of the rearward end of the bracket 210. The bolt 234 may be loosened slightly, and a screwdriver may be inserted between a pin (or post) and the bracket and twisted to shift the bracket about the ball detent 230.

The assemblage of the flow cell assembly 100, the light detector assembly 101 and the block 212 may be adjusted longitudinally with respect to the common axis of the lens assembly by means of a cut-out 246 having a plurality of serrations 245 in the bracket 210 and a notch 250 in the block 212. The bolt and nut 213 may be loosened slightly, and a screwdriver may be inserted between successive serrations and the notch, and twisted to shift the block with respect to the bracket. The rods 216 and 214 project through the block 212 into slots 252 and 254 in the bracket and serve to preclude relative lateral movement therebetween To permit the convenient interconnection of liquid passing conduits to the flow cell 168 a bracket 256 has a horizontal leg 258 pivotally mounted to the rearward end of the block 212 by a machine screw 260. A vertical leg 262 upstands from the leg 258 and has three holes therein into which three conduit junctions 264 may be respectively mounted by snap rings 266. Another vertical leg 268 extends laterally at an angle from the leg 262 and has three holes 270 into which the junctions 264 may be alternatively mounted. Three short lengths of flexible conduit, not shown, may be respectively connected between the three terminations 170, 172 and 176 of the flow cell and the forward terminations of the junctions. The rearward terminations may be coupled by flexible conduits to the treatment manifolds as will be hereinafter described. Depending on which direction, clockwise or counter-clockwise, these latter conduits are to be brought out, the junctions may be mounted in either leg 268 or 262, respectively. A potentiometer 272 may be mounted through a bracket 274 which is fixed to the top of the detector housing by machine screws 194. The various electrical connections to the colorimeter may be brought in through a multicontact plug 278 secured through the base member portion 12. The various liquid connections to the colorimeter may be brought in by conduits through a suitable aperture in the base member, not shown.

To provide the recorder of the analyzer system with standard or reference signals, two of the flow cell assemblies are modified, one associated with a photocell detector, the other associated with a vacuum tube detector. In each case the flow cell 168 is formed as a solid glass body, providing a low light transmittance, but precluding the presence of vapor bubbles. Alternatively, the flow cell may be cut down to include the sight passageway and a portion of bent tubing at each end thereof. A reference fluid is disposed in this cell and the two ends are sealed. No liquid conduits are provided to these two flow cell assemblies.

It will be appreciated that should any leakage occur in the fluid system, any leaked liquid will be drained down to the sloped portions 18 and 16 of the base member 10, whereat the collected liquid may be conveniently drained off from an aperture, not shown, at the apex of these portions.

An exemplary system which provides the samples sequentially to form the initial stream of sequentially flowing samples, which divides the initial stream into a plurality of quotient streams and treats the streams for analysis, which analyzes each of the quotient streams for at least one respective constituent, and which records the results of such analysis, is shown in FIG. 11. Such a system is described in detail in the Skeggs et al article, supra. Briefly, the samples are respectively disposed in containers 300, which are mounted on the indexible turntable 301 of a sampler assembly 302 which includes an off-take tube 303 which is inserted into each container as it is presented thereto. A peristaltic type proportioning pump 304 has a plurality of pump tubes 306, which tubes are concurrently engaged by a plurality of rollers and progressively occluded along their lengths thereby. The pump tubes form part of a manifold which is effective to draw the samples through the off-take tube 303 as an initial flowing stream of sequential samples, to divide the initial stream into a plurality of quotient streams and to treat the streams for analysis, as by dialysis at 308, by gas separation at 310, by the addition of suitable reagents, to

provide a color reaction which is responsive to the concentration of the constituent of interest in each quotient sample. The quotient streams are passed either to the colorimeter 8 or to a flame spectrometer 312. For example, in the colorimeter, the quotient stream in the conduit 314a may be analyzed for albumin by the addition of an H.A.B.A. reagent; the quotient stream in the conduit 3141) may be analyzed for total protein by a biuret reagent; the quotient stream in the conduit 314c may be analyzed for chlorides by a chloride reagent; the quotient stream in the conduit 314d may be analyzed for carbon dioxide by the addition of a C0 reagent after a gas separation at 310; the quotient stream in the conduit 3142 may be analyzed for glucose by an orcinol solution; and the quotient stream in the conduit 314 may be analyzed for urea nitrogen by the addition of diacetyl monoxime and ferric alum reagents. The quotient stream in the conduit 314g may have lithium sulfate added as a standard and may be analyzed for sodium and potassium in the spectrophotometer 312.

A primary chart recorder 320', driven by a null-balancing bridge 322, is utilized to cyclically record the peak value from the analysis of each quotient sample, so that the analyses of each of the quotient samples from the identical initial sample are recorded as a sequential group. To accomplish this, the running time of each of the quotient streams is respectively delayed or phased so that their peaks arrive sequentially at their respective flow cells or the spectrophotometer. A sampling switch 324 is also provided to couple the signal from the respective detector 196 associated with the respective flow cell 1668 to the bridge 322. To monitor the peaking of each sample there is also provided a monitoring or auxiliary recorder 326 which may be coupled by a switch 328 to the detectors of one or a plurality of flow cells for a full cycle of quotient samples. Thus, the monitoring recorder will trace the complete signal provided by a quotient sample from minimum through peak to minimum, while the primary recorder only records a segment of the complete signal, which segment should include the peak.

To permit the shifting of the arrival time of each peak so that it will be passed by the sampling switch 324 to the recorder, all but one of the conduits leading to the flow cells or the spectrophotometer are each provided with means for adjustably varying the length of time it takes for the quotient stream to flow through such a conduit. Such a means is found in the variable volume conduit 330 shown in FIGS. 12 through 16, which shall be called hereinafter a phaser.

The phaser 330 comprises a flat, fixed base plate 332 having two upstanding elements 334 to serve as a hinge bracket. A movable plate 336 is disposed above the base plate 332 and has an outer annular recess 338 and an inner annular recess 340 formed therein confronting said base plate. A resiliently flexible tube 342 is formed into a flat helix and disposed in the outer annular recess 338. The turns may be joined together by a solvent or adhesive to form an integral unit. The recess 338 is provided with a tangential groove 344 to accommodate a continuation 346 of the outermost turn of the helix, and with a transverse bore 348 to accommodate a continuation 350 of the innermost turn of the helix. A bar 352 has one end thereof pivotally mounted between the brackets 334 by a pivot pin 354; and the other end thereof has a slot 356 to receive one end of a threaded rod 358. The other end of the threaded rod 358 is mounted by a pivot pin 360 in a slot 362 to the base plate 332. A nut 364 having handle projections 366 is adapted to be advanced on the rod 358 to bear against the bar 352. A ball bearing 368 is disposed in part in a spherical 370 in the plate 336 and in part in a cylindrical cavity 372 in the plate 352. A machine screw 374 is disposed through the plate 352 into the cavity 372 to adjust the extent of the projection of the ball bearing from the cavity 364. It will be seen that advancement of the nut 364 on the rod 358 against 7 the bar 352 will press the ball bearing 368 against the plate 336, compressing the resiliently flexible tube 342 between the plate 332 and the plate 336, until the confronting faces 368 and 370 of the plates 336 and 332, respectively, abut. Such compression changes the normally circular cross-section area of the resilient tube 342 shown in FIG. 15 into a relatively elliptical cross-section area shown in FIG. 16. It will be appreciated that the length of the tube 342 remains unchanged, and that the internal volume contained by the tube is reduced by the compression from the maximum afforded by the circular cross-section. As the contained volume of the tube is reduced, the residence time required for a given volume of fluid driven at a given volumetric rate of flow to pass through the tube is decreased. Thus, by adjusting the relative compressions on the respective tubes, the quotient samples from the same initial sample may be delayed or advanced to arrive at their respective flow cells in the desired sequence.

The sampling switch 324 comprises a rotary switch having a plurality of decks of contacts. The first contact deck 324A serves to couple in sequence the output signal of each of the flow cell assemblies which receives a quotient sample to one input 322A of the null-balancing bridge 322. The second contact deck 324B serves to couple in sequence the output signal of either a reference flow cell assembly photocell 196 or a reference flow cell assembly vacuum tube detector 198 to the other input 322B of the bridge. The third contact deck 324C serves to couple in sequence the output signal of the unknown photocells 376 of the spectrophotometer 312 to the input 322A of the bridge. The fourth contact deck 324D serves to couple in sequence the output signal of the reference photocells 378 of the spectrophotometer. The fifth contact deck 324E serves to illuminate in sequence each of the indicator lamps 76 to indicate which of the unknown flow cell assemblies is being coupled to the primary recorder 320. The sampling switch 324 makes one full cycle for each initial sample as provided by the sampler assembly 302. The sampler assembly 302 operates a timing earn 380 which actuates a micro-switch to move the sampling switch from its home position.

The monitoring switch 328 serves to couple the output signals from each of the unknown flow cells assemblies of the colorimeter and the unknown photocells 376 of the spectrophotometer to the monitoring recorder 326. The exemplary monitoring recorder is a multi-point recorder having a single stylus 326A with a traversing mechanism 326B which is sequentially and cyclically coupled to three input channels. The switch 328 comprises three cross-bars 328A, any of which can be coupled to any of the input channels 328B by contact pins 328C. The stylus intermittently prints the output curves from three sample channels, each being a substantially smooth curve, during the interval that the primary recorder 320 is not coupled to the respective sample channel. When the primary recorder is coupled to the respective sample channel it changes the impedance of the load on the respective photocell, changing the full scale voltage available to the monitoring recorder. Thus, the traversing mechanism of the monitoring recorder causes its stylus to shift or execute a step function in one direction when the primary recorder is switched onto this respective channel, and causes its stylus to execute a step function in the reverse direction when the primary recorder is switched out of this respective channel. By this double step function, the phasing of the primary recorder sampling interval with respect to the peak or plateau of the optical density of the liquid sample in the respective channel is instantly apparent to the operator, and a permanent record thereof is also automatically created. If the phasing should be changed, the operator need merely vary the respective phaser 330. Obviously, any chart type recorder with one or more stylii may be utilized as the monitoring recorder.

' A'monitoring meter, not shown, may be substituted for the monitoring recorder 326. In such a case,,the operator would have to observe the peak value indicated by the .meter and ensure that this peak occurred during the readout of the flow cell to the recorder 320.

Subject matter including the variable volume conduit disclosed in this application is claimed in the copending patent application of Leonard T. Skeggs and Jack Isreeli, Ser. No. 529,366 filed on Feb. 23,1966 and assigned to a common assignee.

Subject matter including the colorimeter disclosed in this application is claimed in the copending patent application of Jack Isreeli and Richard H. Heimann, Ser. No. 529,466 filed on Feb. 23, 1966 and assigned to a common assignee.

What is claimed is:

1. A process for the analysis of a plurality of sample liquids, comprising: providing the plurality of sample liquids as a flowing stream of successive samples; dividing the stream of successive samples into a plurality of quotient streams, each quotient stream comprising successive subportions of respective samples; analyzing each of the quotient streams at an analysis means and providing a plurality of signals each respectively responsive to the characteristic of interest in each respective stream; cyclically recording a chronological portion of each of the plurality of signals; and, during a cycle of said recording, indicating an additional chronological portion of at least one of said signals, said additional chronological portion chronologically overlapping said first mentioned chronological portion of said one of said signals 2. A process according to claim 1 further comprising: while indicating said additional chronological portion, also indicating in correlation therewith the chronological extent of said first mentioned respective chronological portion of said one of said signals which is being recorded.

3. A process according to claim 1 wherein said indicating of said additional chronological portion is effected by recording said one of said signals, and further including recording in superimposed fashion on the recording of said additional portion in correlation therewith an indication of the chronological extent of said first mentioned chronological portion of said one of said signals which is being recorded.

4. A process according to claim 4 wherein recording of said first mentioned chronological portion is effected by a primary recording means coupled to the source of said signal during the chronolgical extent only of said first mentioned portion, and recording of said additional chronological portion is eifected by an auxiliary recording means coupled to said source, said primary recording means providing a load on said source and said auxiliary recording means when coup ed to said source during recording of said first mentioned chronological portion of said signal to vary the loading on said source thus change the magnitude of the full-scale signal available to said auxiliary recording means.

5. A recording, multiple channel, analysis apparatus comprising: a plurality of analysis means, each of said ana ysis means including means for receiving a sample stream and means for providing a signal responsive to a characteristic thereof; primary recording means coupled to said plurality of analysis means for recording a chronological portion of each of the signals respectively provided by said plurality of analysis means; and auxiliary indicating means coupled to at' least one of said plurality of analysis means for indicating an additional chronological portion of the signal'provided by said coupled analysis means, said additional chronological portion chronologically overlapping said first mentioned respective chronological p'ortion'of'said one signal provided by said coupled analysis means.

6. Apparatus according to'claim 5 wherein said auxiliary indicating means and said primary recording means are intercoupled, whereby said primary recording means causes said auxiliary indicating means to provide indicia responsive to and indicative of the concurrent recording of the same signal from the same respective analysis means.

7. Apparatus according to claim 5 wherein said auxiliary indicating means is a chart recorder having a stylus and a traversing mechanism therefor, and said primary recording means is a chart recorder having a stylus and a traversing mechanism therefor; said auxiliary traversing mechanism being selectively couplable to one of said plurality of analysis means and traversing its stylus in response to the signal provided thereto; said primary traversing mechanism being automatically couplable in sequence to each of said plurality of analysis means during a full cycle and traversing its stylus in response to each of the signals provided thereto; whereby when both of said traversing mechanisms are concurrently coupled to the same analysis means the signal provided to said auxiliary traversing mechanism is modified, causing said auxiliary recorder to indicate the chronological extent of such concurrent coupling.

8. Apparatus according to claim 7 wherein said primary recorder, when coupled to the same analysis means as said auxiliary recorder, changes the electrical loading on said analysis means, thereby modifying the full scale voltage provided to said auxiliary recorder.

9. Apparatus according to claim 7 wherein said auxiliary recorder is adapted to be concurrently coupled to a selected group of said plurality of analysis means, and to indicate the respective concurrent coupling to each analysis means of said group by said primary recorder.

10. A process according to claim 1 wherein the chronological extent of said additional chronological portion is substantially equal to the entirety of the respective one of said signals provided by the respective analysis means during a recording cycle.

11. Apparatus according to claim 5 wherein said primary recorder means further includes means to cyclically record a portion of the signals respectively provided by said plurality of analysis means.

References Cited UNITED STATES PATENTS 3/1966 Skeggs et a1. 

